160: Superficial Fungal Infection Flashcards
What are the three forms of mycoses?
The three forms of mycoses are superficial, subcutaneous, and deep/systemic.
What defines a superficial fungal infection?
A superficial fungal infection is defined as a dermatophyte infection of keratinized tissues including skin, hair, and nails.
Which genera of dermatophytes are most commonly isolated in the United States?
The most commonly isolated genera of dermatophytes in the United States are Trichophyton, Microsporum, and Epidermophyton.
What is the most common cause of dermatophytosis of the skin?
The most common cause of dermatophytosis of the skin is Trichophyton rubrum.
What is onychomycosis?
Onychomycosis is the term used for dermatophytosis of the nails.
What are the common diagnostic methods for confirming dermatophytosis?
Common diagnostic methods for confirming dermatophytosis include microscopic examination, culture, Wood light evaluation, and histopathology.
What are the typical treatments for infections involving hair-bearing skin and nails?
Infections involving hair-bearing skin and nails typically require oral treatment with antifungals, while several topical and oral antifungals are available for effective treatment of dermatophytosis.
What is the significance of anthrophilic dermatophytes?
Anthrophilic dermatophytes are typically restricted to human hosts and are transmitted via direct contact.
What are the characteristics of zoophilic dermatophyte infections?
Zoophilic dermatophyte infections are transmitted to humans from animals such as cats, dogs, rabbits, guinea pigs, birds, horses, and cattle. They typically cause acute and intense inflammatory responses in humans.
What is the difference between zoophilic and geophilic dermatophyte infections?
- Zoophilic: Transmitted from animals to humans, causing acute inflammatory responses.
- Geophilic: Sporadic human infections occur upon direct contact with soil, resulting in intense inflammatory responses.
What are the common clinical features associated with dermatophytosis?
Clinical features of dermatophytosis vary depending on the causative dermatophyte and the site of infection. Common diagnoses include:
Infection Type | Description |
|—————-|————-|
| Tinea barbae | Infection of the beard area |
| Tinea capitis | Scalp infection |
| Tinea corporis | Body infection |
| Tinea cruris | Groin infection |
| Tinea favosa | Honeycomb-like infection |
| Tinea manuum | Hand infection |
| Tinea nigra | Dark patches on skin |
| Tinea pedis | Athlete’s foot |
| Piedra | Hair infection |
| Onychomycosis | Nail infection |
What factors contribute to the pathogenesis of dermatophyte infections?
The pathogenesis of dermatophyte infections involves several factors:
- Adherence: Successful adherence of arthroconidia to keratin.
- Invasion: Trauma and maceration facilitate penetration through the skin.
- Enzymatic Activity: Secretion of enzymes (proteases, lipases) that aid in invasion and nutrient acquisition.
- Host Response: Involves both innate and adaptive immune responses, including antimicrobial peptides and specific immune responses.
What is the epidemiology of dermatophyte infections in the United States?
In the United States:
- Trichophyton tonsurans replaced Microsporum audouinii as the most common cause of tinea capitis in the latter half of the 20th century.
- M. canis has become the second most common cause of tinea capitis.
- Dermatophyte infections are 5 times more prevalent in males than females.
How does HIV infection affect dermatophytosis severity?
In individuals with HIV, the severity of dermatophytosis appears to be increased, while the prevalence of infections does not change significantly.
What is the difference between zoophilic and geophilic dermatophytes?
Zoophilic dermatophytes are transmitted from animals, while geophilic dermatophytes cause sporadic human infections upon direct contact with soil.
What is the most common cause of tinea capitis in the United States in the latter half of the 20th century?
Trichophyton tonsurans replaced Microsporum audouinii as the most common cause of tinea capitis.
What is the prevalence of dermatophyte infections in males compared to females?
Dermatophyte infections are five times more prevalent in males than females.
What are some clinical features of dermatophytosis?
Clinical features vary depending on the causative dermatophyte and the site of infection, including conditions like tinea barbae, tinea capitis, and onychomycosis.
What role does adherence play in the pathogenesis of dermatophyte infections?
Adherence is the first step for dermatophytes, where arthroconidia attach to keratin, leading to alterations in gene expression necessary for infection.
What is the host response to dermatophyte infections?
The host response includes both nonspecific and specific immune responses, involving various immune cells and antimicrobial peptides.
What is the significance of cell-mediated immunity in dermatophyte infections?
Cell-mediated immunity results in a specific delayed-type hypersensitivity response against invading fungi, which is crucial for controlling infections.
What genetic polymorphisms are associated with an increased risk of invasive fungal disease?
Polymorphisms of TLR1 and TLR4 are associated with increased risk of invasive fungal disease.
What are the key steps in performing a KOH examination for dermatophytosis?
- Collect scale by scraping the involved area with a dull edge (e.g., a no. 15 blade).
- Place scrapings on a glass slide and cover with a coverslip.
- Prepare with 10% to 20% KOH and place several drops of KOH adjacent to the coverslip edge.
- Allow capillary action to wick the fluid under the coverslip.
- Optionally, aid penetration of KOH by slightly warming the slide or adding dimethylsulfoxide (DMSO).
What are the three possible patterns of infection observed in hair during microscopic examination?
The three possible patterns of infection are:
Pattern | Description |
|————|————————————————–|
| Ectothrix | Small or large arthroconidia forming a sheath around the hair shaft |
| Endothrix | Arthroconidia within the hair shaft |
| Favus | Hyphae and air spaces within the hair shaft |
What is the significance of using a blue or black stain during KOH examination?
Adding a drop of blue or black stain such as chlorazol black helps in better identifying fungal elements during the KOH examination.
What is the role of Dectin-1 and CARD-9 mutations in fungal infections?
They are associated with chronic mucocutaneous candidiasis and chronic dermatophyte infections due to decreased IL-17 production.
What is the purpose of using KOH preparation in diagnosing dermatophytosis?
To visualize septate and branching hyphae in skin, hair, or nails.
What is a common issue with KOH examination results in dermatophytosis?
It may yield false-negative results in up to 15% of cases.
How should a KOH examination be performed on the skin?
By scraping the involved area with a dull edge and placing the scrapings on a glass slide with KOH.
What can aid the penetration of KOH into keratin during examination?
Slightly warming the slide with a low-intensity flame or adding dimethylsulfoxide (DMSO).
What additional staining can help identify fungal elements during KOH examination?
Adding a drop of blue or black stain such as chlorazol black.
What are the three possible patterns of infection in hair shafts?
(a) Ectothrix, (b) Endothrix, (c) Favus.
What is the most commonly used isolation medium for dermatophytes and what is its purpose?
Sabouraud dextrose agar (SDA) is the most commonly used isolation medium for dermatophytes, serving as the medium on which most morphologic descriptions are based.
What are the key components added to Sabouraud dextrose agar to eliminate contaminants?
The key components added to Sabouraud dextrose agar to eliminate contaminants are cycloheximide and chloramphenicol (± gentamicin).
How long does it typically take to culture Epidermophyton floccosum and Trichophyton verrucosum?
It takes 5 to 7 days for Epidermophyton floccosum and up to 4 weeks for Trichophyton verrucosum to culture.
What is the purpose of histopathology in the diagnosis of dermatophytoses?
Histopathology is used to aid in the diagnosis of Majocchi granuloma and to confirm the presence of hyphae involving hair shafts in conditions like tinea capitis.
What is the significance of periodic acid-Schiff (PAS) staining in dermatophyte diagnosis?
Periodic acid-Schiff (PAS) staining highlights hyphae that may otherwise be subtle in appearance on routine staining, making it a useful diagnostic tool.
What are the treatment options available for dermatophytoses?
Multiple systemic and topical antifungal agents are available to treat dermatophytoses of skin, hair, and nails, with oral treatment typically required for dermatoses involving hair-bearing skin and nails.
What factors influence the clinical course and prognosis of dermatophyte infections?
The clinical course and prognosis of dermatophyte infections vary according to pathogen and host factors, including the ability of some dermatophytes to evade or suppress host immune function.
What is the most commonly used isolation medium for dermatophytes?
Sabouraud dextrose agar (SDA).
What is the purpose of adding cycloheximide and chloramphenicol to the culture medium?
To eliminate contaminant molds, yeast, and bacteria.
How long does it typically take to culture Epidermophyton floccosum?
5 to 7 days.
What is the alternative isolation medium that contains the pH indicator phenol red?
Dermatophyte test medium.
What test can differentiate dermatophytes based on their ability to hydrolyze urea?
Urease test.
What is the role of histopathology in diagnosing dermatophytoses?
It is not often employed but can aid in diagnosing conditions like Majocchi granuloma.
What is the most specific test for onychomycosis?
Culture of nail clippings.
What type of treatment is typically required for dermatoses involving hair-bearing skin and nails?
Oral treatment.
What factors can affect the clinical course and prognosis of dermatophyte infections?
Pathogen and host factors.
How can some dermatophytes affect the host immune function?
They can evade or suppress host immune function.
What are the systemic treatment options for Tinea capitis in adults?
- Griseofulvin: 20 to 25 mg/kg/day for 6 to 8 weeks
- Terbinafine: 250 mg/day for 2 to 8 weeks
- Itraconazole: 5 mg/kg/day for 2 to 4 weeks
- Fluconazole: 6 mg/kg once weekly for 3 to 6 weeks
What topical treatments are recommended for Tinea corporis/cruris?
- Allylamines
- Imidazoles
- Tolnaftate
- Butenafine
- Ciclopirox
- Gentian violet
What is the recommended systemic treatment for Onychomycosis in adults?
- Terbinafine: 250 mg/day for 6 to 12 weeks
- Itraconazole: 200 mg/day for 2 to 3 months, or 400 mg daily for 1 week/month for 2 to 3 months
- Fluconazole: 150 to 300 mg/week for 3 to 6 months
What are the systemic treatment options for Tinea pedis/manuum in adults?
- Terbinafine: 250 mg/day for 2 weeks
- Itraconazole: 200 mg daily for 1 week
- Fluconazole: 150 to 300 mg/week for 2 to 4 weeks
What is the systemic treatment for Tinea capitis in adults?
Griseofulvin 20 to 25 mg/kg/day for 6 to 8 weeks, Terbinafine 250 mg/day for 2 to 8 weeks, Itraconazole 5 mg/kg/day for 2 to 4 weeks, Fluconazole 6 mg/kg/day for 3 to 6 weeks.
What topical treatments are recommended for Tinea barbae?
Zinc pyrithione 1% or 2% and Povidone-iodine 2.5%.
What is the recommended systemic treatment for Tinea corporis/cruris in adults?
Terbinafine 250 mg/day for 2 to 4 weeks, Itraconazole 200 mg/day for 2 to 4 weeks, Fluconazole 150 mg/day for 2 to 4 weeks.
What is the treatment for Onychomycosis in adults?
Ciclopirox, Amorolfine, Itraconazole, and Efinaconazole.
What is the systemic treatment for Tinea pedis/manuum in adults?
Terbinafine 250 mg/day for 2 weeks, Itraconazole 200 mg daily for 1 week.
What is the treatment for Onychomycosis in adults?
Terbinafine 250 mg/day for 2 to 4 weeks, Itraconazole 200 mg/day for 2 to 4 weeks, Fluconazole 150 mg/day for 2 to 4 weeks.
What is the systemic treatment for Tinea pedis/manuum in adults?
Terbinafine 250 mg/day for 2 weeks, Itraconazole 200 mg daily for 2 to 3 months, Fluconazole 150 mg/week for 2 to 3 weeks.
What is the recommended treatment duration for Griseofulvin in children with Tinea capitis?
Daily for 6 to 8 weeks.
What is the systemic treatment for Tinea corporis in children?
Griseofulvin 1 mg/day for 6 weeks.
What is the recommended treatment for Tinea pedis in children?
Terbinafine 3 to 6 mg/kg/day for 2 weeks.
What is the systemic treatment for Onychomycosis in children?
Terbinafine daily for 6 to 12 weeks, depending on weight.
What are the indications for using Fluconazole as an oral antifungal agent?
Fluconazole is indicated for:
- Onychomycosis
- Tinea barbae
- Tinea capitis
- Tinea corporis/cruris
- Tinea pedis/manuum
What are the adverse effects associated with Griseofulvin?
The adverse effects of Griseofulvin include:
- Headache
- Gastrointestinal upset
Caution: liver impairment
What is the pregnancy category for Itraconazole and what are its indications?
Itraconazole is classified as Pregnancy category C. Its indications include:
- Onychomycosis
- Tinea barbae
- Tinea capitis
- Tinea corporis/cruris
- Tinea pedis/manuum
What monitoring is required for Terbinafine when used as an oral antifungal agent?
Monitoring for Terbinafine includes:
- Liver function tests baseline and at 1 month
- Watch for gastrointestinal upset, taste disturbance, and elevation of liver enzymes
What is the recommended administration for Amorolfine in treating onychomycosis?
Amorolfine should be applied 1 to 2 times per week after gentle nail filing for up to 12 months.
What are the uses of Ciclopirox and its administration guidelines?
Ciclopirox is used for:
- Tinea corporis, cruris, pedis, and versicolor
- Seborrheic dermatitis
Administration: Apply twice daily.
What precautions should be taken when using Clotrimazole?
Clotrimazole should be applied twice daily for 1 to 4 weeks. It is classified as Pregnancy category B.
What is the pregnancy category for Butenafine and its recommended use?
Butenafine is classified as Pregnancy category C. It is recommended to be applied 1 to 2 times daily for 1 to 4 weeks for Tinea corporis, cruris, and pedis.
What is the drug class of Fluconazole?
Triazole
What are the indications for Griseofulvin?
Tinea barbae, Tinea capitis (first-line Microsporum), Tinea corporis/cruris, Tinea pedis/manuum
What is a common adverse effect of Itraconazole?
GI upset
What is the pregnancy category of Terbinafine?
Pregnancy category B
What is the formulation of Amorolfine?
Liquid, 250 mg/5 mL
What is the use of Butenafine?
Tinea corporis, cruris, pedis, versicolor
How often should Ciclopirox be applied?
Apply twice daily
What is the administration instruction for Clotrimazole?
Apply twice daily for 1 to 4 weeks
What is the pregnancy category for Econazole?
Pregnancy category C
What is the primary use of Efinaconazole and how is it administered?
Efinaconazole is primarily used for onychomycosis and is administered as a solution (10%), applied daily for 48 weeks.
What are the uses and administration guidelines for Ketoconazole?
Ketoconazole is used for tinea corporis, cruris, pedis, versicolor, cutaneous Candida, and seborrheic dermatitis. It is available in various formulations (cream, foam, gel, shampoo) and should be applied 1 to 2 times daily. For shampoo, it should be applied 5 to 10 minutes prior to rinsing and used 2 to 3 times/week as prophylaxis.
What precautions should be taken when using Miconazole?
Miconazole is used for tinea corporis, cruris, and pedis. It should be applied twice daily for 4 weeks. Precautions include that it is classified as Pregnancy category not classified and should be used with caution in children ≥2 years of age.
What is the recommended administration for Terbinafine and its uses?
Terbinafine is used for tinea corporis, cruris, pedis, and versicolor. It should be applied 1 to 2 times daily for 1 to 2 weeks.
What are the uses and administration instructions for Zinc pyrithione?
Zinc pyrithione is used for tinea capitis and barbae as well as seborrheic dermatitis. It should be used at least 2 times/week.
What is the use of Efinaconazole?
Onychomycosis.
What is the administration frequency for Gentian violet?
1 to 2 times daily.
What conditions does Ketoconazole treat?
Tinea corporis, cruris, pedis, versicolor, cutaneous Candida, seborrheic dermatitis.
How often should Miconazole be applied for Tinea corporis and cruris?
Twice daily for 4 weeks.
What is the use of Povidone-iodine?
Tinea capitis and seborrheic dermatitis.
What is the administration recommendation for Selenium sulfide?
Foam: twice daily; Shampoo: apply, wait 5 to 10 minutes prior to rinsing.
What is the use of Terbinafine?
Tinea corporis, cruris, pedis, and cutaneous candidiasis.
What is the recommended application frequency for Tioconazole?
Twice daily for 6 to 12 months.
What is the use of Tolnaftate?
Tinea corporis, cruris, and pedis.
What is the administration frequency for Zinc pyrithione?
Use at least 2 times/week.
What is the dermatophyte (ID) reaction and its clinical features?
The dermatophyte (ID) reaction is an inflammatory dermatitis occurring at sites distant from primary dermatophytosis, affecting 4% to 5% of patients. It is associated with a delayed-type hypersensitivity response to Trichophyton antigens. Clinical features include:
- Polymorphic appearance, ranging from follicular or nonfollicular papules to vesicles on hands and feet.
- Reactive erythemas such as erythema nodosum and urticaria.
- KOH examination and culture are negative.
Criteria for diagnosis:
1. Dermatophytosis on another part of the body.
2. Absence of fungal elements from the ID eruption.
3. Resolution of the ID eruption with clearing of the primary dermatophyte infection.
What are the different types of onychomycosis and their clinical features?
Onychomycosis is a fungal infection of the nail caused by dermatophytes, nondermatophyte molds, or yeasts. The clinical features include:
Type of Onychomycosis | Description |
|————————————-|—————————————————————————–|
| Distolateral Subungual Type | Most common; discoloration, thickening, and subungual debris of toenails. |
| Proximal Subungual Type | Discoloration and thickening of the proximal nail; screening for HIV is recommended. |
| White Superficial Type | Irregular opaque white patches on various parts of the nail plates. |
| Other Clinical Presentation | Primary total dystrophic onychomycosis caused by Candida. |
Epidemiology: Most prevalent nail disease, accounting for 50% of onychodystrophy cases, affecting up to 14% of the population.
What are the management options for onychomycosis?
Management options for onychomycosis include:
- Systemic therapy: Oral antifungals; griseofulvin is no longer standard due to prolonged treatment and low cure rates.
- Topical therapy: Recommended for patients with distal nail involvement or contraindications for systemic treatment.
- Combination therapy: Higher clearance rates than either oral or topical treatments alone.
- Mechanical intervention: Includes trimming, debridement, nail bed curettage, and nail abrasion. For refractory cases, options include laser treatment, surgical avulsion, or chemical removal of the nail with 40% urea compounds combined with topical or oral antifungals.
What is piedra and what are its types?
Piedra is an asymptomatic superficial fungal infection of the hair shaft, also known as trichomycosis nodularis. There are two types of piedra:
- Black piedra: Caused by Piedraia hortae.
- White piedra: Caused by pathogenic species of the genus Trichosporon.
A patient presents with distal nail discoloration, thickening, and subungual debris. What is the diagnosis, and what is the most common causative organism?
The diagnosis is Distolateral Subungual Onychomycosis. The most common causative organism is Trichophyton rubrum.
A patient presents with a chronic dermatophyte infection of the nails characterized by irregular opaque white patches on the nail plates. What is the diagnosis, and what is the recommended treatment for mild cases?
The diagnosis is White Superficial Onychomycosis. Mild cases can be treated with topical antifungals.
A patient presents with a dermatophyte infection of the nails characterized by discoloration and thickening of the proximal nail. What is the diagnosis, and what underlying condition should be screened for?
The diagnosis is Proximal Subungual Onychomycosis. The patient should be screened for HIV, as this condition has been identified as a marker for the disease.
A patient presents with a dermatophyte infection of the nails characterized by discoloration, thickening, and subungual debris of the distal aspect of the toenails. What is the diagnosis, and what is the most effective treatment?
The diagnosis is Distolateral Subungual Onychomycosis. The most effective treatment is systemic antifungal therapy.
A patient presents with a dermatophyte infection of the nails characterized by multiple patterns, including proximal subungual and white superficial types. What is the diagnosis, and what is the recommended treatment approach?
The diagnosis is Onychomycosis with multiple patterns. The recommended treatment approach is combination therapy, which has a higher clearance rate than either oral or topical treatments alone.
A patient presents with a dermatophyte infection of the nails characterized by green or black discoloration under the nail. What is the diagnosis, and what is the causative organism?
The diagnosis is secondary bacterial infection of the nail. The causative organism is Pseudomonas aeruginosa.
A patient presents with a dermatophyte infection of the nails characterized by hyphae seen between the nail laminae parallel to the surface. What is the diagnosis, and what diagnostic test can confirm it?
The diagnosis is Onychomycosis. The diagnostic test that can confirm it is PAS staining of nail clippings.
A patient presents with a dermatophyte infection of the nails characterized by irregular opaque white patches on various parts of the nail plates. What is the diagnosis, and what is the causative organism?
The diagnosis is White Superficial Onychomycosis. The causative organism is Trichophyton rubrum.
A patient presents with a dermatophyte infection of the nails characterized by discoloration and thickening of the proximal nail. What is the diagnosis, and what is the recommended diagnostic test?
The diagnosis is Proximal Subungual Onychomycosis. The recommended diagnostic test is KOH examination of subungual debris.
A patient presents with a dermatophyte infection of the nails characterized by discoloration, thickening, and subungual debris of the distal aspect of the toenails. What is the diagnosis, and what is the causative organism?
The diagnosis is Distolateral Subungual Onychomycosis. The causative organism is Trichophyton rubrum.
What is the ID reaction associated with in dermatophytosis?
A delayed-type hypersensitivity response to the Trichophyton test.
What are the clinical features of onychomycosis?
What is the causative organism of a dermatophyte infection?
The causative organism is Pseudomonas aeruginosa.
What is the diagnosis for a patient with a dermatophyte infection of the nails characterized by hyphae seen between the nail laminae?
The diagnosis is Onychomycosis.
The diagnostic test that can confirm it is PAS staining of nail clippings.
What are the clinical features of onychomycosis?
Discoloration, thickening, and subungual debris of the nails.
What is the most common type of onychomycosis?
Distolateral Subungual Type.
What is the epidemiology of onychomycosis?
It is the most prevalent nail disease, accounting for approximately 50% of all causes of onychodystrophy, affecting up to 14% of the population.
What is the role of Candida species in onychomycosis?
Candida species are responsible for up to 30% of fingernail cases.
What is the recommended management for onychomycosis?
Systemic therapy with oral antifungals, topical therapy for distal nail involvement, and mechanical intervention for refractory cases.
What causes black piedra?
It is caused by Piedraia hortae.
What is white piedra caused by?
Pathogenic species of the hair shaft.
What are the clinical findings associated with black piedra?
Black piedra presents as firmly attached, hard or gritty, brown-black colored concretions on the hair shaft that vary in size.
How does white piedra differ from black piedra in terms of appearance and clinical findings?
White piedra appears as softer and less-adherent whitish to beige-colored concretions that may coalesce into sleeve-like structures along the hair shaft.
What is the recommended management for both black and white piedra?
The best treatment for both black and white piedra is shaving, supplemented with topical azole.
What are the common clinical features of tinea barbae?
Tinea barbae predominantly affects the beard area in males and presents unilaterally on the face.
What is the epidemiology of tinea capitis in children?
Tinea capitis primarily affects children between the ages of 3 and 14 years, with a prevalence of approximately 4% in the United States.
What are the treatment options for tinea barbae?
Treatment for tinea barbae typically includes oral antifungals, which are usually necessary, along with topical antifungals.
What is the diagnosis for a patient with a beard area infection characterized by sharply demarcated red edematous nodules?
The diagnosis is the kerion type of Tinea Barbae.
Treatment includes oral antifungals and systemic glucocorticoids during the first week of therapy.
What is the primary cause of black piedra and where is it commonly found?
Black piedra is caused by the Trichosporon genus and is commonly found in tropical areas of South America.
What are the clinical findings associated with white piedra?
White piedra presents as softer, less-adherent whitish to beige-colored concretions on the hair shaft.
How does the diagnosis of black piedra differ from white piedra?
Black piedra shows a firm attachment with gritty concretions, while white piedra has softer, less-adherent structures.
What is the epidemiology of tinea barbae?
Tinea barbae predominantly affects the beard area of males.
What are the clinical features of tinea capitis?
Tinea capitis results in hair loss and scaling with varying degrees of inflammatory response.
What type of lesions are associated with the kerion type of tinea barbae?
The kerion type presents as sharply demarcated red edematous nodules studded with yellowish weeping pustules.
What is the significance of KOH preparation in diagnosing piedra infections?
KOH preparation helps visualize the arrangement of hyphae and the structure of the nodules.
What are the three main patterns of hair infection by dermatophytes in tinea capitis?
- Ectothrix - Yellow-green fluorescence detected under Wood lamp examination.
- Endothrix - No fluorescence on Wood lamp.
- Favus - Characterized by longitudinally arranged hyphae.
What are the clinical features associated with ‘Black Dot’ Tinea Capitis?
- Hair shafts are broken off at the scalp level, leaving behind grouped black dots.
What is the recommended management for tinea capitis?
- Topical therapy alone is not recommended; empiric oral treatment should be initiated based on local epidemiology.
What are the differential diagnoses for tinea capitis?
- Most Likely:
- Seborrheic dermatitis
- Contact dermatitis
- Pustular or plaque psoriasis
- Atopic dermatitis
- Bacterial pyoderma
- Folliculitis
- Decalvans
- Lichen planopilaris
- Dissecting cellulitis of the scalp.
What is the diagnosis for a 10-year-old child with a large, round, hyperkeratotic plaque of alopecia on the scalp?
The diagnosis is the ‘gray patch’ type of noninflammatory Tinea Capitis.
A Wood lamp examination can confirm it by showing green fluorescence.
What is the diagnosis for a patient with a dermatophyte infection of the scalp characterized by grouped black dots?
The diagnosis is ‘Black Dot’ Tinea Capitis.
The causative pattern of infection is endothrix.
What is the diagnosis for a patient with a dermatophyte infection of the scalp characterized by inflammatory papules?
The diagnosis is the inflammatory type of Tinea Capitis.
Initial treatment includes empiric oral antifungal therapy.
What is the diagnosis for a patient with a dermatophyte infection of the skin characterized by follicular papules?
The diagnosis is Majocchi Granuloma.
A common predisposing factor is the application of topical corticosteroids.
What is the appearance of the scalp in cases of Tinea Capitis?
It gives the appearance of a mowed wheat field with patches of polygonal-shaped alopecia.
What type of fluorescence is observed in hair shafts affected by Tinea Capitis?
A yellow-green fluorescence may be detected in ectothrix infections.
What is Tinea Cruris and how is it characterized?
Tinea Cruris is dermatophytosis of the groin, genitalia, pubic area, and perineal and perianal skin.
It is characterized by annular erythematous plaques with a raised scaling border.
What are the diagnostic methods for Tinea Cruris?
Diagnosis of Tinea Cruris can be made using KOH, Wood lamp, fungal culture, and biopsy.
What is Tinea Favosa and what are its clinical features?
Tinea Favosa is a chronic dermatophyte infection of the scalp characterized by thick yellow crusts (scutula).
How is Tinea Nigra diagnosed?
Diagnosis of Tinea Nigra is made using KOH, which reveals brown to olive-colored, thick branching hyphae.
What is the most common type of dermatophytosis and how is it acquired?
Tinea pedis is the most common dermatophytosis, approximately 10%, and is acquired through direct contact.
What is the likely diagnosis for a patient with a chronic dermatophyte infection of the scalp characterized by thick yellow crusts?
The likely diagnosis is Tinea Favosa.
It is associated with malnutrition and poor hygiene.
What is the diagnosis for a patient with annular erythematous plaques with a raised scaling border?
The diagnosis is Tinea Cruris.
Exacerbating factors include occlusion and humidity.
What is the diagnosis for a patient with asymptomatic, mottled brown to greenish-black macules on the palms?
The diagnosis is Tinea Nigra.
A KOH preparation can confirm it.
What is the diagnosis for a patient with a dermatophyte infection of the groin and pubic area characterized by bilateral annular plaques?
The diagnosis is Tinea Cruris.
Lifestyle modifications include wearing loose-fitted clothing.
What is the diagnosis for a patient with a dermatophyte infection of the scalp characterized by patchy perifollicular erythema?
The diagnosis is Tinea Favosa.
Under a Wood lamp, subtle blue-gray fluorescence along the entire hair shaft is characteristic.
What is the diagnosis for a patient with a dermatophyte infection of the skin characterized by annular plaques?
The diagnosis is Tinea Corporis.
First-line treatment includes topical antifungals.
What are the common treatment options for isolated plaques on the glabrous skin?
Topical allylamines, imidazoles, tolnaftate, butenafine, and ciclopirox are effective.
What exacerbates Tinea Cruris infections?
Direct contact, humidity, and occlusion.
What are the common clinical features of Tinea Favosa?
Thick yellow crusts (scutula) within hair follicles leading to scarring alopecia.
What is the treatment for Tinea Nigra?
Topical therapy with a keratolytic, such as Whitfield ointment.
What are the features of Tinea Favosa?
Thick yellow crusts (scutula) within hair follicles leading to scarring alopecia.
How is Tinea Nigra diagnosed?
Using KOH to identify brown to olive-colored, thick branching hyphae and yeast cells.
What is the most common dermatophytosis?
Tinea pedis, which is acquired through direct contact with an infected person or animal, the soil, or via autoinoculation.
What is the treatment for Tinea Nigra?
Topical therapy with a keratolytic, such as Whitfield ointment or salicylic acid.
What is the characteristic appearance of Tinea Favosa?
Patchy perifollicular erythema with slight scaling and matting of the hair, leading to yellow-red follicular papules.
What is the differential diagnosis for Tinea Cruris?
Includes erythrasma, cutaneous candidiasis, intertrigo, contact dermatitis, inverse psoriasis, seborrheic dermatitis, and folliculitis.
What are the clinical features of the Interdigital type of Tinea Pedis?
The Interdigital type of Tinea Pedis is characterized by:
- Maceration of the interdigital space
- Opaque white scales
- Erosions between the lateral third and fourth and fourth and fifth toes
- Interdigital erosions with pruritus and malodor, commonly referred to as ‘athlete’s foot.’
What is the treatment for mild interdigital Tinea Pedis without bacterial involvement?
Mild interdigital Tinea Pedis without bacterial involvement is treated topically with:
- Allylamine
- Imidazole
- Ciclopirox
- Benzylamine
- Tolnaftate
- Undecanoic acid-based creams.
Terbinafine cream applied twice daily for 1 week is effective in 66% of cases.
What are the characteristics of the Vesiculobullous type of Tinea Pedis?
The Vesiculobullous type of Tinea Pedis features:
- Tense vesicles larger than 3 mm in diameter
- Vesiculopustules or bullae on the soles and periplantar areas.
What is the significance of Gram-negative bacterial superinfection in the Acute Ulcerative type of Tinea Pedis?
In the Acute Ulcerative type of Tinea Pedis, Gram-negative bacterial superinfection can lead to:
- Production of vesicles, pustules, and purulent ulcers on the plantar surface
- Associated conditions such as cellulitis, lymphangitis, lymphadenopathy, and fever.
What diagnostic methods are used for Tinea Pedis?
The diagnostic methods for Tinea Pedis include:
- KOH (potassium hydroxide) preparation
- Fungal culture
- Biopsy.
What is the diagnosis for a patient with diabetes mellitus presenting with vesicles, pustules, and purulent ulcers on the plantar surface?
The diagnosis is the acute ulcerative type of Tinea Pedis with Gram-negative bacterial superinfection. Treatment should include topical or systemic antibacterial agents based on culture and sensitivity, and dilute acetoacetic acid soaks may help reduce the risk of cellulitis.
What is the diagnosis for a patient with vesicles larger than 3 mm in diameter on the soles?
The diagnosis is the vesiculobullous type of Tinea Pedis. Initial symptomatic treatment may include topical or systemic corticosteroids during the initial period of antifungal treatment.
What is the diagnosis for a patient with a dermatophyte infection of the feet characterized by macerated interdigital spaces?
The diagnosis is the interdigital type of Tinea Pedis. First-line treatment includes topical antifungal creams such as terbinafine applied twice daily for one week.
What is the diagnosis for a patient with a dermatophyte infection of the hands characterized by diffuse dry scaling?
The diagnosis is Tinea Manuum. Diagnostic tests include KOH preparation, fungal culture, and biopsy.
What is the most common presentation of Tinea Pedis?
Most commonly only 1 hand, concomitant with infection of feet and toenails, referred to as two feet – one hand syndrome.
What characterizes the interdigital type of Tinea Pedis?
The interdigital space is macerated with opaque white scales and has erosions between the lateral third and fourth and fourth and fifth toes.
What is a characteristic feature of the chronic hyperkeratotic (moccasin) type of Tinea Pedis?
Patchy erythema and scaling in a moccasin distribution on the foot, with an arciform pattern of scales.
What are the features of the vesiculobullous type of Tinea Pedis?
Features tense vesicles larger than 3 mm in diameter, vesiculopustules, or bullae on the soles and periplantar areas.
What does the acute ulcerative type of Tinea Pedis produce in combination with Gram-negative bacterial superinfection?
Produces vesicles, pustules, and purulent ulcers on the plantar surface, often associated with cellulitis, lymphangitis, lymphadenopathy, and fever.
What is the recommended treatment for mild interdigital Tinea Pedis without bacterial involvement?
Treated topically with allylamine, imidazole, ciclopirox, benzylamine, tolnaftate, or undecanoic acid-based creams.
What is the significance of onychomycosis in relation to Tinea Pedis?
Associated onychomycosis is common and requires more durable oral treatment to prevent recurrence of Tinea Pedis.
What diagnostic methods are used for Tinea Pedis?
KOH, fungal culture, and biopsy.
What is a common reaction associated with vesiculobullous and acute ulcerative types of Tinea Pedis?
A vesicular id reaction, either on the lateral foot or toes, or on the lateral aspects of the fingers.
What should be done for Gram-negative coinfections in Tinea Pedis?
They should be treated with a topical or systemic antibacterial agent based on culture and sensitivity.
